Consider an experiment to determine the effect of a single factor that can be set to a levels. At each factor setting n measurements of the quality characteristic are taken. The j th measurement of the quality characteristic at factor level i is denoted yij . What is the number of degrees of freedom of SSError

(n-1)a

Step-by-step explanation:

In this question we have a single factor with number of levels equal to a.

Then the Number of observations that are within each factor setting is equal to n.

So the total number of observations = na.

We have the degrees of freedom for SS(Error) = n - k,

Now, n is the total number of observations,

While,

k is the number of levels of the single factor.

Therefore the degrees of freedom is = na - a

= (n - 1)a.